scsi.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

/*
 *  scsi.c Copyright (C) 1992 Drew Eckhardt
 *         Copyright (C) 1993, 1994, 1995 Eric Youngdale
 *
 *  generic mid-level SCSI driver
 *      Initial versions: Drew Eckhardt
 *      Subsequent revisions: Eric Youngdale
 *
 *  <[e-mail]>
 *
 *  Bug correction thanks go to :
 *      Rik Faith <[e-mail]>
 *      Tommy Thorn <tthorn>
 *      Thomas Wuensche <[e-mail]>
 *
 *  Modified by Eric Youngdale [e-mail] to
 *  add scatter-gather, multiple outstanding request, and other
 *  enhancements.
 *
 *  Native multichannel, wide scsi, /proc/scsi and hot plugging 
 *  support added by Michael Neuffer <[e-mail]>
 *
 *  Added request_module("scsi_hostadapter") for kerneld:
 *  (Put an "alias scsi_hostadapter your_hostadapter" in /etc/conf.modules)
 *  Bjorn Ekwall  <[e-mail]>
 *
 *  Major improvements to the timeout, abort, and reset processing,
 *  as well as performance modifications for large queue depths by
 *  Leonard N. Zubkoff <[e-mail]>
 */

/*
 * Don't import our own symbols, as this would severely mess up our
 * symbol tables.
 */
#define _SCSI_SYMS_VER_

#include <linux/config.h>
#include <linux/module.h>

#include <linux/sched.h>
#include <linux/timer.h>
#include <linux/string.h>
#include <linux/malloc.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
#include <linux/stat.h>
#include <linux/blk.h>
#include <linux/interrupt.h>
#include <linux/delay.h>

#include <asm/system.h>
#include <asm/irq.h>
#include <asm/dma.h>

#include "scsi.h"
#include "hosts.h"
#include "constants.h"

#ifdef CONFIG_KERNELD
#include <linux/kerneld.h>
#endif

#undef USE_STATIC_SCSI_MEMORY

/*
static const char RCSid[] = "$Header: /cvsroot/hurd/gnumach/linux/dev/drivers/scsi/Attic/scsi.c,v 1.1 1999/04/26 05:44:26 tb Exp $";
*/


/* Command groups 3 and 4 are reserved and should never be used.  */
const unsigned char scsi_command_size[8] = { 6, 10, 10, 12, 12, 12, 10, 10 };

#define INTERNAL_ERROR (panic ("Internal error in file %s, line %d.\n", __FILE__, __LINE__))

/*
 * PAGE_SIZE must be a multiple of the sector size (512).  True
 * for all reasonably recent architectures (even the VAX...).
 */
#define SECTOR_SIZE		512
#define SECTORS_PER_PAGE	(PAGE_SIZE/SECTOR_SIZE)

#if SECTORS_PER_PAGE <= 8
 typedef unsigned char	FreeSectorBitmap;
#elif SECTORS_PER_PAGE <= 32
 typedef unsigned int	FreeSectorBitmap;
#else
# error You lose.
#endif

static void scsi_done (Scsi_Cmnd *SCpnt);
static int update_timeout (Scsi_Cmnd *, int);
static void print_inquiry(unsigned char *data);
static void scsi_times_out (Scsi_Cmnd * SCpnt);
static int scan_scsis_single (int channel,int dev,int lun,int * max_scsi_dev ,
                 int * sparse_lun, Scsi_Device ** SDpnt, Scsi_Cmnd * SCpnt,
                 struct Scsi_Host *shpnt, char * scsi_result);
void scsi_build_commandblocks(Scsi_Device * SDpnt);

#ifdef CONFIG_MODULES
extern struct symbol_table scsi_symbol_table;
#endif

static FreeSectorBitmap * dma_malloc_freelist = NULL;
static int scsi_need_isa_bounce_buffers;
static unsigned int dma_sectors = 0;
unsigned int dma_free_sectors = 0;
unsigned int need_isa_buffer = 0;
static unsigned char ** dma_malloc_pages = NULL;

static int time_start;
static int time_elapsed;
static volatile struct Scsi_Host * host_active = NULL;
#define SCSI_BLOCK(HOST) ((HOST->block && host_active && HOST != host_active) \
			  || (HOST->can_queue && HOST->host_busy >= HOST->can_queue))

const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] =
{
    "Direct-Access    ",
    "Sequential-Access",
    "Printer          ",
    "Processor        ",
    "WORM             ",
    "CD-ROM           ",
    "Scanner          ",
    "Optical Device   ",
    "Medium Changer   ",
    "Communications   "
};


/*
 * global variables :
 * scsi_devices an array of these specifying the address for each
 * (host, id, LUN)
 */

Scsi_Device * scsi_devices = NULL;

/* Process ID of SCSI commands */
unsigned long scsi_pid = 0;

static unsigned long serial_number = 0;

static unsigned char generic_sense[6] = {REQUEST_SENSE, 0,0,0, 255, 0};
static void resize_dma_pool(void);

/* This variable is merely a hook so that we can debug the kernel with gdb. */
Scsi_Cmnd * last_cmnd = NULL;

/* This is the pointer to the /proc/scsi code. 
 * It is only initialized to !=0 if the scsi code is present 
 */ 
#if CONFIG_PROC_FS 
extern int (* dispatch_scsi_info_ptr)(int ino, char *buffer, char **start, 
				      off_t offset, int length, int inout); 
extern int dispatch_scsi_info(int ino, char *buffer, char **start, 
			      off_t offset, int length, int inout); 

struct proc_dir_entry proc_scsi_scsi = {
    PROC_SCSI_SCSI, 4, "scsi",
    S_IFREG | S_IRUGO | S_IWUSR, 1, 0, 0, 0, 
    NULL,
    NULL, NULL,
    NULL, NULL, NULL
};
#endif

/*
 *  This is the number  of clock ticks we should wait before we time out
 *  and abort the command.  This is for  where the scsi.c module generates
 *  the command, not where it originates from a higher level, in which
 *  case the timeout is specified there.
 *
 *  ABORT_TIMEOUT and RESET_TIMEOUT are the timeouts for RESET and ABORT
 *  respectively.
 */

#ifdef DEBUG_TIMEOUT
static void scsi_dump_status(void);
#endif


#ifdef DEBUG
    #define SCSI_TIMEOUT (5*HZ)
#else
    #define SCSI_TIMEOUT (2*HZ)
#endif

#ifdef DEBUG
    #define SENSE_TIMEOUT SCSI_TIMEOUT
    #define ABORT_TIMEOUT SCSI_TIMEOUT
    #define RESET_TIMEOUT SCSI_TIMEOUT
#else
    #define SENSE_TIMEOUT (5*HZ/10)
    #define RESET_TIMEOUT (5*HZ/10)
    #define ABORT_TIMEOUT (5*HZ/10)
#endif

#define MIN_RESET_DELAY (2*HZ)

/* Do not call reset on error if we just did a reset within 15 sec. */
#define MIN_RESET_PERIOD (15*HZ)

/* The following devices are known not to tolerate a lun != 0 scan for
 * one reason or another.  Some will respond to all luns, others will
 * lock up. 
 */

#define BLIST_NOLUN     0x01
#define BLIST_FORCELUN  0x02
#define BLIST_BORKEN    0x04
#define BLIST_KEY       0x08
#define BLIST_SINGLELUN 0x10
#define BLIST_NOTQ	0x20
#define BLIST_SPARSELUN 0x40
#define BLIST_MAX5LUN	0x80

struct dev_info{
    const char * vendor;
    const char * model;
    const char * revision; /* Latest revision known to be bad.  Not used yet */
    unsigned flags;
};

/*
 * This is what was previously known as the blacklist.  The concept
 * has been expanded so that we can specify other types of things we
 * need to be aware of.
 */
static struct dev_info device_list[] =
{
{"TEAC","CD-R55S","1.0H", BLIST_NOLUN},         /* Locks up if polled for lun != 0 */
{"CHINON","CD-ROM CDS-431","H42", BLIST_NOLUN}, /* Locks up if polled for lun != 0 */
{"CHINON","CD-ROM CDS-535","Q14", BLIST_NOLUN}, /* Locks up if polled for lun != 0 */
{"DENON","DRD-25X","V", BLIST_NOLUN},           /* Locks up if probed for lun != 0 */
{"HITACHI","DK312C","CM81", BLIST_NOLUN},       /* Responds to all lun - dtg */
{"HITACHI","DK314C","CR21" , BLIST_NOLUN},      /* responds to all lun */
{"IMS", "CDD521/10","2.06", BLIST_NOLUN},       /* Locks-up when LUN>0 polled. */
{"MAXTOR","XT-3280","PR02", BLIST_NOLUN},       /* Locks-up when LUN>0 polled. */
{"MAXTOR","XT-4380S","B3C", BLIST_NOLUN},       /* Locks-up when LUN>0 polled. */
{"MAXTOR","MXT-1240S","I1.2", BLIST_NOLUN},     /* Locks up when LUN>0 polled */
{"MAXTOR","XT-4170S","B5A", BLIST_NOLUN},       /* Locks-up sometimes when LUN>0 polled. */
{"MAXTOR","XT-8760S","B7B", BLIST_NOLUN},       /* guess what? */
{"MEDIAVIS","RENO CD-ROMX2A","2.03",BLIST_NOLUN},/*Responds to all lun */
{"MICROP", "4110", "*", BLIST_NOTQ},		/* Buggy Tagged Queuing */
{"NEC","CD-ROM DRIVE:841","1.0", BLIST_NOLUN},  /* Locks-up when LUN>0 polled. */
{"RODIME","RO3000S","2.33", BLIST_NOLUN},       /* Locks up if polled for lun != 0 */
{"SANYO", "CRD-250S", "1.20", BLIST_NOLUN},     /* causes failed REQUEST SENSE on lun 1 
						 * for aha152x controller, which causes 
						 * SCSI code to reset bus.*/
{"SEAGATE", "ST157N", "\004|j", BLIST_NOLUN},   /* causes failed REQUEST SENSE on lun 1 
						 * for aha152x controller, which causes 
						 * SCSI code to reset bus.*/
{"SEAGATE", "ST296","921", BLIST_NOLUN},        /* Responds to all lun */
{"SEAGATE","ST1581","6538",BLIST_NOLUN},	/* Responds to all lun */
{"SONY","CD-ROM CDU-541","4.3d", BLIST_NOLUN},
{"SONY","CD-ROM CDU-55S","1.0i", BLIST_NOLUN},
{"SONY","CD-ROM CDU-561","1.7x", BLIST_NOLUN},
{"TANDBERG","TDC 3600","U07", BLIST_NOLUN},     /* Locks up if polled for lun != 0 */
{"TEAC","CD-ROM","1.06", BLIST_NOLUN},          /* causes failed REQUEST SENSE on lun 1 
						 * for seagate controller, which causes 
						 * SCSI code to reset bus.*/
{"TEXEL","CD-ROM","1.06", BLIST_NOLUN},         /* causes failed REQUEST SENSE on lun 1 
						 * for seagate controller, which causes 
						 * SCSI code to reset bus.*/
{"QUANTUM","LPS525S","3110", BLIST_NOLUN},      /* Locks sometimes if polled for lun != 0 */
{"QUANTUM","PD1225S","3110", BLIST_NOLUN},      /* Locks sometimes if polled for lun != 0 */
{"MEDIAVIS","CDR-H93MV","1.31", BLIST_NOLUN},   /* Locks up if polled for lun != 0 */
{"SANKYO", "CP525","6.64", BLIST_NOLUN},        /* causes failed REQ SENSE, extra reset */
{"HP", "C1750A", "3226", BLIST_NOLUN},          /* scanjet iic */
{"HP", "C1790A", "", BLIST_NOLUN},              /* scanjet iip */
{"HP", "C2500A", "", BLIST_NOLUN},              /* scanjet iicx */

/*
 * Other types of devices that have special flags.
 */
{"SONY","CD-ROM CDU-8001","*", BLIST_BORKEN},
{"TEXEL","CD-ROM","1.06", BLIST_BORKEN},
{"IOMEGA","Io20S         *F","*", BLIST_KEY},
{"INSITE","Floptical   F*8I","*", BLIST_KEY},
{"INSITE","I325VM","*", BLIST_KEY},
{"NRC","MBR-7","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"NRC","MBR-7.4","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"REGAL","CDC-4X","*", BLIST_MAX5LUN | BLIST_SINGLELUN},
{"NAKAMICH","MJ-4.8S","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"NAKAMICH","MJ-5.16S","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"PIONEER","CD-ROM DRM-600","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"PIONEER","CD-ROM DRM-602X","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"PIONEER","CD-ROM DRM-604X","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"EMULEX","MD21/S2     ESDI","*", BLIST_SINGLELUN},
{"CANON","IPUBJD","*", BLIST_SPARSELUN},
{"MATSHITA","PD","*", BLIST_FORCELUN | BLIST_SINGLELUN},
{"YAMAHA","CDR100","1.00", BLIST_NOLUN},	/* Locks up if polled for lun != 0 */
{"YAMAHA","CDR102","1.00", BLIST_NOLUN},	/* Locks up if polled for lun != 0 */
{"nCipher","Fastness Crypto","*", BLIST_FORCELUN},
/*
 * Must be at end of list...
 */
{NULL, NULL, NULL}
};

static int get_device_flags(unsigned char * response_data){
    int i = 0;
    unsigned char * pnt;
    for(i=0; 1; i++){
	if(device_list[i].vendor == NULL) return 0;
	pnt = &response_data[8];
	while(*pnt && *pnt == ' ') pnt++;
	if(memcmp(device_list[i].vendor, pnt,
		  strlen(device_list[i].vendor))) continue;
	pnt = &response_data[16];
	while(*pnt && *pnt == ' ') pnt++;
	if(memcmp(device_list[i].model, pnt,
		  strlen(device_list[i].model))) continue;
	return device_list[i].flags;
    }
    return 0;
}

void scsi_make_blocked_list(void)  {
    int block_count = 0, index;
    unsigned long flags;
    struct Scsi_Host * sh[128], * shpnt;
    
    /*
     * Create a circular linked list from the scsi hosts which have
     * the "wish_block" field in the Scsi_Host structure set.
     * The blocked list should include all the scsi hosts using ISA DMA.
     * In some systems, using two dma channels simultaneously causes
     * unpredictable results.
     * Among the scsi hosts in the blocked list, only one host at a time
     * is allowed to have active commands queued. The transition from
     * one active host to the next one is allowed only when host_busy == 0
     * for the active host (which implies host_busy == 0 for all the hosts
     * in the list). Moreover for block devices the transition to a new
     * active host is allowed only when a request is completed, since a
     * block device request can be divided into multiple scsi commands
     * (when there are few sg lists or clustering is disabled).
     *
     * (DB, 4 Feb 1995)
     */
    
    save_flags(flags);
    cli();
    host_active = NULL;
    
    for(shpnt=scsi_hostlist; shpnt; shpnt = shpnt->next) {
	
#if 0
	/*
	 * Is this is a candidate for the blocked list?
	 * Useful to put into the blocked list all the hosts whose driver
	 * does not know about the host->block feature.
	 */
	if (shpnt->unchecked_isa_dma) shpnt->wish_block = 1;
#endif
	
	if (shpnt->wish_block) sh[block_count++] = shpnt;
    }
    
    if (block_count == 1) sh[0]->block = NULL;
    
    else if (block_count > 1) {
	
	for(index = 0; index < block_count - 1; index++) {
	    sh[index]->block = sh[index + 1];
	    printk("scsi%d : added to blocked host list.\n",
		   sh[index]->host_no);
	}
	
	sh[block_count - 1]->block = sh[0];
	printk("scsi%d : added to blocked host list.\n",
	       sh[index]->host_no);
    }
    
    restore_flags(flags);
}

static void scan_scsis_done (Scsi_Cmnd * SCpnt)
{
    
#ifdef DEBUG
    printk ("scan_scsis_done(%p, %06x)\n", SCpnt->host, SCpnt->result);
#endif
    SCpnt->request.rq_status = RQ_SCSI_DONE;
    
    if (SCpnt->request.sem != NULL)
	up(SCpnt->request.sem);
}

#ifdef CONFIG_SCSI_MULTI_LUN
static int max_scsi_luns = 8;
#else
static int max_scsi_luns = 1;
#endif

void scsi_luns_setup(char *str, int *ints) {
    if (ints[0] != 1)
	printk("scsi_luns_setup : usage max_scsi_luns=n (n should be between 1 and 8)\n");
    else
	max_scsi_luns = ints[1];
}

/*
 *  Detecting SCSI devices :
 *  We scan all present host adapter's busses,  from ID 0 to ID (max_id).
 *  We use the INQUIRY command, determine device type, and pass the ID /
 *  lun address of all sequential devices to the tape driver, all random
 *  devices to the disk driver.
 */
static void scan_scsis (struct Scsi_Host *shpnt, unchar hardcoded,
                 unchar hchannel, unchar hid, unchar hlun)
{
  int dev, lun, channel;
  unsigned char scsi_result0[256];
  unsigned char *scsi_result;
  Scsi_Device *SDpnt;
  int max_dev_lun, sparse_lun;
  Scsi_Cmnd *SCpnt;

  SCpnt = (Scsi_Cmnd *) scsi_init_malloc (sizeof (Scsi_Cmnd), GFP_ATOMIC | GFP_DMA);
  SDpnt = (Scsi_Device *) scsi_init_malloc (sizeof (Scsi_Device), GFP_ATOMIC);
  memset (SCpnt, 0, sizeof (Scsi_Cmnd));


  /* Make sure we have something that is valid for DMA purposes */
  scsi_result = ( ( !shpnt->unchecked_isa_dma )
                 ? &scsi_result0[0] : scsi_init_malloc (512, GFP_DMA));

  if (scsi_result == NULL) {
    printk ("Unable to obtain scsi_result buffer\n");
    goto leave;
  }

  /* We must chain ourself in the host_queue, so commands can time out */
  if(shpnt->host_queue)
      shpnt->host_queue->prev = SCpnt;
  SCpnt->next = shpnt->host_queue;
  SCpnt->prev = NULL;
  shpnt->host_queue = SCpnt;


  if (hardcoded == 1) {
    Scsi_Device *oldSDpnt=SDpnt;
    struct Scsi_Device_Template * sdtpnt;